Dynamics of solutes with hydrodynamic interactions: Comparison between Brownian dynamics and stochastic rotation dynamics simulations
Dynamics of solutes with hydrodynamic interactions: Comparison between Brownian dynamics and stochastic rotation dynamics simulations
复制标题
DOI：
10.1103/physreve.88.043304
复制
发表时间：
2013-10-16
影响因子：
2.4
通讯作者：
Jardat, M.
中科院分区：
文献类型：
--
作者：
Batot, G.;Dahirel, V.;Jardat, M.
溶液或悬浮液中颗粒的动力学受到热波动和流体动力相互作用的影响。存在几种介观方法来解释这些溶剂引起的效应，例如具有流体动力学相互作用的布朗动力学和混合分子动力学-随机旋转动力学方法。在这里，我们比较了两种将溶质与溶剂耦合的方法，即随机旋转动力学 (SRD) 和布朗动力学，有和没有显式流体动力学相互作用。在第一个 SRD 方案 [具有碰撞耦合 (CC) 的 SRD] 中，溶质参与与溶剂的碰撞步骤，而在第二个方案 [具有中心力耦合 (CFC) 的 SRD] 中，溶质通过直接力与溶剂相互作用，产生滑移边界条件。我们比较了通过这些模拟方案获得的模型系统中中性和带电溶质的传输系数。使用没有流体动力学相互作用的布朗动力学作为参考来量化流体动力学对通过不同方法建模的输运系数的影响。我们表明，在稀范围内，SRD CFC 方法提供的结果类似于布朗动力学的结果，其中扩散系数和电导率具有流体动力相互作用。 SRD CC 方案预测的扩散系数接近于没有流体动力学相互作用的布朗动力学模拟所获得的扩散系数，但考虑了流体动力学对电导率的部分影响。
The dynamics of particles in solution or suspension is influenced by thermal fluctuations and hydrodynamic interactions. Several mesoscale methods exist to account for these solvent-induced effects such as Brownian dynamics with hydrodynamic interactions and hybrid molecular dynamics-stochastic rotation dynamics methods. Here we compare two ways of coupling solutes to the solvent with stochastic rotation dynamics (SRD) to Brownian dynamics with and without explicit hydrodynamic interactions. In the first SRD scheme [SRD with collisional coupling (CC)] the solutes participate in the collisional step with the solvent and in the second scheme [SRD with central force coupling (CFC)] the solutes interact through direct forces with the solvent, generating slip boundary conditions. We compare the transport coefficients of neutral and charged solutes in a model system obtained by these simulation schemes. Brownian dynamics without hydrodynamic interactions is used as a reference to quantify the influence of hydrodynamics on the transport coefficients as modeled by the different methods. We show that, in the dilute range, the SRD CFC method provides results similar to those of Brownian dynamics with hydrodynamic interactions for the diffusion coefficients and for the electrical conductivity. The SRD CC scheme predicts diffusion coefficients close to those obtained by Brownian dynamic simulations without hydrodynamic interactions, but accounts for part of the influence of hydrodynamics on the electrical conductivity.